Filter



Feb.. 7 1939.y H. c. EDWARDS ET AL 2,146,205

' FILTER I Filed May 14, 19,37

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THE/f? HTTopA/E.

Peiesfea Fea?, .1939

UNITED STATES PATENT oFFicE ken Roller Bearing corporation of hioCompany, Canton, Ohio, a

Application May 14. 1937, serian No. 14am calme. (o1. cremes) E fspe'ctive semi-cylindrical, end pieces` or dams 8 This invention relatesto filters, particularly filters for the injection systems of internalcombustion engines.' of the Diesel type.- It has for its principalobjctsto provide the fuel supply passageway of such a system with a simple andA eihcient lter of economical construction and vcompact.' design. `.Theinvention consists in .the-

iilterin'g element and in the construction, combi-r 'nations andarrangements of parts hereinafter described and claimed \In theaccompanying drawing, which forms part of this specification and whereinlike symvbols referto like parts Wherever they occur,

Fig. 1 1s a part sideelevauonal and part longif tudinal sectional vviewof a fuel injector provided view similar to Fig. 1,

Fig,- 3 .is a central longitudinal section on the line 3--3 in F18. 2, i

Figs. 4 and 5' are cross-sections on the lines l 4 4 and 5 5,respectively, 'in Fig. 2; and

Fig. 6 is a perspective view of one of thel end, pieces for closing oneend of the helical grooves of the filtering element. l For purposes ofillustration, our invention is shown in and ,embodied in a fuel injectorl of the kind used for supplying fluid'fuel to anV internal.

combustion engine of the compression-ignition type. Said injector has afuel supply passageway 2 therein leading to a4 discharge -oriiice 3lcorrtrolled by a spring-loaded, hydraulically operated plunger valve l.This construction of fuel injector' is well known and it is consideredunnecessary to illustrate it in detail.

According to the present invention, the fuel supply jfpa'ssageway 2 hagacylindrical ltering element A mounted therein having double helicall`ribs 5 that tsaid passageway andform a helical inlet groove E andahelical outlet groove 1."

"I'he end of the helical inlet groove 6 that faces the direction ohfuelilow is left open; and the opposite end of said groove is closed by asemidouble helical ri-b to the required diameter.

pressure supplied by the usual injection pumpcli` (not shown), entersthe open end of the helical inlet groove 6 and follows said groove untilstopped by the semi-cylindrical end piece or dani 8 -at the rear endthereof. 'I'he fuel, after filling said inlet groove is then forcedbylthe pressure exerted thereon between the wall of the fuel supplypassageway and the peripheral surface of the double helical rib 5 intothe helical outlet groove 1 and thence iiows through the open end ofsaid groove into said passageway. The double helical rib 5 is accuratelyground to provide a fairly close iit in the fuel discharge passageway'li! and thus serves to hold back or strain out the sediment which mightinterfere with the operation of the injector, which sediment is retainedin moved from the fuel supply passageway.

The hereinbefore described filtering device has several advantages; itcan be easily and economi- N vcally manufactured; it is adapted for usein passageways of small diameter; it can be readily removed, cleaned andreplaced; and the filtering action can -beeasily controlled by grindingthe What we claim is:

` 1. A member 'a passageway with a smoth portion and means in saidpassageway for filtering fluid passing therethrough, said meanscomprising a member 'fitting the smooth portion of said passageway andhaving two external helical `grooves therein, one ofsaid grooves beingclosed at one end of said member and the other of said grooves beingclosed at the opposite end of said member, said member being made from aflat strip twisted into the form of a double helix having separate endmembers rigid therewith that constitute closures for said ends of saidgrooves;

2. A fuel injector having va. fuel delivery pas-- sageway with smoothportionand means in saidl passageway vfor ltering uid passingtherethrough, said means comprising a member fitting the smooth portionof said passageway and having two external helical grooves therein, oneof said grooves being closed at one end of said` member and the other ofsaidgrooves beingclosed at the opposite end of said member, said memberbeing made frbm aat'strip twisted into the form of a double helix withits end portions left fiat and having semi-cylindrical members securedthereto that constitute closures i'or saidy ends of said grooves.

3. An element for a iter of the kind described comprising a thin striptwisted to form two helical grooves and having its ends left flat andmembers secured to said iiat ends `l'for closing one groove at one endof said element and the other groove atthe opposite end of said element.

4. An element for a illter of the kind described comprising a strip vofsheet metal twisted to form two helical grooves and having its ends lettiiat, semi-cylindrical end members for closing one groove at one endoi.' said element and the other groove at the other end of said element,said end members having slots therein adapted to receive the fiat endsof said strip, and welds for securing said ends in said slots.

5. A member having a passageway with a smooth portion and means in saidpassageway for mtering uid passing therethrough, said means comprisinga. member fitting the smooth portion of said passageway and having twoexthat constitute closures for said ends of said grooves, said membershaving slots therein adapted to receive the fiat ends of said strip, andwelds for securing said ends in said slots.

HERBERT C. EDWARDS. ALBERT F. CAMPBELL

